1.1.3.5 Ligand field effects, high-spin and low-spin compounds and crossover situations

2005 ◽  
pp. 10-11
Author(s):  
E. König ◽  
G. König
Keyword(s):  
High Spin ◽  
Ligand Field ◽  
Field Effects

The influence of ligand field effects on the magnetic exchange of high-spin Co(ii)-semiquinonate complexes

2006 ◽  
pp. 722-729 ◽  
Author(s):  
Alessandro Bencini ◽  
Alessandra Beni ◽  
Ferdinando Costantino ◽  
Andrea Dei ◽  
Dante Gatteschi ◽  
...  
Keyword(s):  
High Spin ◽  
Ligand Field ◽  
Magnetic Exchange ◽  
Field Effects

scholarly journals Correlating Axial and Equatorial Ligand Field Effects to the Single-Molecule Magnet Performances of a Family of Dysprosium Bis-Methanediide Complexes

2021 ◽  
Author(s):  
Lewis Thomas-Hargreaves ◽  
Marcus Giansiracusa ◽  
Matthew Gregson ◽  
Emanuele Zanda ◽  
Felix O'Donnell ◽  
...  
Keyword(s):  
Alkali Metal ◽  
Single Molecule ◽  
Ligand Field ◽  
Single Molecule Magnet ◽  
Field Effects ◽  
Equatorial Ligand ◽  
Metal Alkyls

Treatment of the new methanediide-methanide complex [Dy(SCS)(SCSH)(THF)] (1Dy, SCS = {C(PPh2S)2}2-) with alkali metal alkyls and auxillary ethers produces the bis-methanediide complexes [Dy(SCS)2][Dy(SCS)2(K(DME)2)2] (2Dy), [Dy(SCS)2][Na(DME)3] (3Dy) and [Dy(SCS)2][K(2,2,2-cryptand)] (4Dy). For...

scholarly journals Ligand Field Effects on the Ground and Excited States of the Catalytically Active FeO2+ Species

2018 ◽  
Author(s):  
Justin K. Kirkland ◽  
Shahriar N. Khan ◽  
Bryan Casale ◽  
Evangelos Miliordos ◽  
Konstantinos Vogiatzis
Keyword(s):  
Excited States ◽  
Function Theory ◽  
Weak Field ◽  
Ligand Field ◽  
Model Complexes ◽  
Coordination Environment ◽  
Reactivity Descriptors ◽  
Field Effects ◽  
Catalytically Active ◽  
High Level

<p>We have performed high-level wave function theory calculations on bare FeO2+ and a series of non-heme Fe(IV)-oxo model complexes in order to elucidate the electronic properties and the ligand field effects on those channels. Our results suggest that a coordination environment formed by a weak field gives access to both competitive channels, yielding more reactive Fe(IV)-oxo sites. On the contrary, a strong ligand environment stabilizes only the σ-channel. Our concluding remarks will aid on the derivation of new structure-reactivity descriptors that can contribute on the development of the next generation of functional catalysts.</p>

scholarly journals Ligand Field Effects on the Ground and Excited States of the Catalytically Active FeO2+ Species

2018 ◽  
Author(s):  
Justin K. Kirkland ◽  
Shahriar N. Khan ◽  
Bryan Casale ◽  
Evangelos Miliordos ◽  
Konstantinos Vogiatzis
Keyword(s):  
Excited States ◽  
Function Theory ◽  
Weak Field ◽  
Ligand Field ◽  
Model Complexes ◽  
Coordination Environment ◽  
Reactivity Descriptors ◽  
Field Effects ◽  
Catalytically Active ◽  
High Level

<p>We have performed high-level wave function theory calculations on bare FeO2+ and a series of non-heme Fe(IV)-oxo model complexes in order to elucidate the electronic properties and the ligand field effects on those channels. Our results suggest that a coordination environment formed by a weak field gives access to both competitive channels, yielding more reactive Fe(IV)-oxo sites. On the contrary, a strong ligand environment stabilizes only the σ-channel. Our concluding remarks will aid on the derivation of new structure-reactivity descriptors that can contribute on the development of the next generation of functional catalysts.</p>

Unusual ligand field effects in square-planar cobalt(II) complexes of quadridentate Schiff bases

1985 ◽  
Vol 24 (8) ◽  
pp. 1159-1165 ◽  
Author(s):  
A. Ceulemans ◽  
M. Dendooven ◽  
L. G. Vanquickenborne
Keyword(s):  
Schiff Bases ◽  
Ligand Field ◽  
Field Effects ◽  
Square Planar

Ab InitioCalculations on KNiF3: Ligand-Field Effects

1972 ◽  
Vol 5 (11) ◽  
pp. 4291-4301 ◽  
Author(s):  
A. J. H. Wachters ◽  
W. C. Nieuwpoort
Keyword(s):  
Ligand Field ◽  
Field Effects

Metal acetylacetonates: Interpretation of infrared spectra and new evidence for ligand field effects

1967 ◽  
Vol 3 (2) ◽  
pp. 51-55 ◽  
Author(s):  
R.D. Hancock ◽  
H.W. Sacks ◽  
Rosemary Thornton ◽  
David A. Thornton
Keyword(s):  
Infrared Spectra ◽  
Ligand Field ◽  
Metal Acetylacetonates ◽  
Field Effects ◽  
New Evidence

scholarly journals Purification and Characterization of an Iron Superoxide Dismutase and a Catalase from the Sulfate-Reducing BacteriumDesulfovibrio gigas

2000 ◽  
Vol 182 (3) ◽  
pp. 796-804 ◽  
Author(s):  
Wagner G. Dos Santos ◽  
Isabel Pacheco ◽  
Ming-Yih Liu ◽  
Miguel Teixeira ◽  
António V. Xavier ◽  
...  
Keyword(s):  
Superoxide Dismutase ◽  
High Spin ◽  
Specific Activity ◽  
Ligand Field ◽  
Strictly Anaerobic ◽  
Oxygen Utilization ◽  
Epr Spectrum ◽  
Paramagnetic Resonance ◽  
Sulfate Reducing ◽  
Link Type

ABSTRACT The iron-containing superoxide dismutase (FeSOD; EC 1.15.1.1 ) and catalase (EC 1.11.1.6 ) enzymes constitutively expressed by the strictly anaerobic bacterium Desulfovibrio gigas were purified and characterized. The FeSOD, isolated as a homodimer of 22-kDa subunits, has a specific activity of 1,900 U/mg and exhibits an electron paramagnetic resonance (EPR) spectrum characteristic of high-spin ferric iron in a rhombically distorted ligand field. Like other FeSODs from different organisms, D. gigas FeSOD is sensitive to H2O2 and azide but not to cyanide. The N-terminal amino acid sequence shows a high degree of homology with other SODs from different sources. On the other hand, D. gigas catalase has an estimated molecular mass of 186 ± 8 kDa, consisting of three subunits of 61 kDa, and shows no peroxidase activity. This enzyme is very sensitive to H2O2and cyanide and only slightly sensitive to sulfide. The native enzyme contains one heme per molecule and exhibits a characteristic high-spin ferric-heme EPR spectrum (g y,x = 6.4, 5.4); it has a specific activity of 4,200 U/mg, which is unusually low for this class of enzyme. The importance of these two enzymes in the context of oxygen utilization by this anaerobic organism is discussed.

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